With an electronic throttle device disclosed in the following Patent Document 1, a throttle body including a throttle valve is integrally molded with an intake air manifold, being made of resin material, and a driving part including a motor for rotating the throttle valve and a gear mechanism for transmitting power of the motor to the throttle valve is connected to the throttle body by welding. Further, with an air intake device disclosed in the following Patent Document 2, a connection pipe formed in a throttle body which integrally includes a motor for rotating a throttle valve is screwed to a connection pipe holding part formed in an intake air manifold, and a flange in the throttle body is fastened to that in the intake air manifold with a bolt, thereby the throttle body including a driving part being connected to the intake air manifold.
Patent document 1: Japanese Unexamined Patent Application Publication No. 2005-233146
Patent document 2: Japanese Unexamined Patent Application Publication No. 2010-116794